But shutdown had to happen eventually. The probe landed further north than any previous Martian lander and as winter sets in and the days shorten it is no longer receiving enough light during the day to charge its batteries. Dustier skies, more cloud cover and gathering cold also contributed to its demise.

It has been a busy five months. In that time, Phoenix has sent back more than 25,000 images. It has verified the presence of water-ice under the surface. It has operated the first atomic force microscope ever used on another world. It has found small quantities of salts that could be substrates for life. And it made the puzzling discovery of perchlorate salts.

The Latin epitaph was the winner of a competition run by Wired to write the catchiest sign-off less than 140 characters long. My favourite, though – from a certain D. Adams – was "So long and thanks for all the ice".